The present invention relates to an atomizer spray plate of a fuel oil atomizer for pressure-type atomization systems, including spill return systems, and simplex, or "once-through" systems.
For environmental and economical reasons, there is an ongoing need to improve the efficiency of fuel oil atomizers which supply fuel oil to a furnace. It is known that the formation of NO.sub.x can be slowed by providing fuel-rich and fuel-lean zones in the atomizing spray pattern. Such a fuel spray pattern can be achieved by imparting a rotational momentum, or swirl, to the fuel as it exits the atomizer, and by shaping the fuel spray in a specific manner.
For example, U.S. Pat. No 5,622,489 to Monro discloses a fuel atomizer with an oblong discharge slot that is shaped to achieve a spray pattern with fuel-rich zones that are spaced apart from one another and separated by a central fuel-lean zone. However, the shaping of the oblong slot is rather complex as the width and angle of the walls of the slot must be precisely set.
Accordingly, it would be desirable to provide a low NO.sub.x fuel oil atomizer with an atomizer spray plate that provides a spray pattern with fuel-rich and fuel-lean zones, yet does not require complex machining of the discharge slot. It would further be desirable to have a method for fabricating such an atomizer spray plate. Furthermore, the fuel oil atomizer should be compatible with pressure-type atomization systems, including spill return systems and simplex systems.
The present invention provides an apparatus and method having the above and other advantages.